/sci/ - Science & Math

Science is based on logic
Philosophy is based on reasoning
You can prove what water is made of, a building block of life, but you can’t prove the purpose or justification of life. Philosophy is mainly deductive reason and observation but also has factors of faith needed in it. Science changes constantly and old ideas are thrown away for new ones.

I am in no way an expert on electricity so that means it's confusing af! I just saw a video on how a variac functions and he uses a lightbulb to demonstrate. Transformers output the same power but at different voltages/current (assuming there's no loss), so if thats true how can if he's outputting 5 volts, the variac is stepping it down, the lightbulb has a constant resistance so that means it should be really bright? Since lightbulbs at 120v operate normally with idk how much current going through, shouldn't decreasing the voltage with the same power increase the bulb's luminosity because of more current going through? Same power coming from the mains? This is so confusing.